At&t MicroCell & NAT can't connect.

[dovad]

I am having great difficulty getting my at&t MicroCell to connect and initialize.  Part of my issue is that the MicroCell sets up an ipsec VPN back to at&t and the ports that it requires are:

123 - time
443 - SSL
500 - VPN key
4500 - ipsec tunnel

I am also running a WebDAV server with SSL on port 443 on a different subnet and when I setup an alias with the IP addresses of both my WebDAV server as well as the MicroCell for port 443 there was conflict and a couple of my users complained that the WebDAV server did not work.

I do have a subnet that is totally untrusted where the MicroCell resides that I'd really like to work as a DMZ in the Linksys sense.  I tried to configure this but when I go to the grc.com's "shieldsup" site the above 4 ports all show up as stealthed on the proposed DMZ subnet.

I've attached screenshots of the rules to allow everything to the DMZ subnet and block DMZ to LAN access.

In the near future I'd also like to add an ipsec VPN to work with iOS devices and my laptop so am hoping that a solution can be found to allow all these future plans.  I thought that the DMZ would be best because I can just hang the MicroCell and a Blu-Ray player and any future untrusted gadgets on that subnet.

I'm using version 1.2.3-Release.

Please help…

Thanks...
Dave